A catheter assembly may have more than one lumen, and usually such a multilumen catheter has an extension tube connected to the proximal end of each of the lumens on that portion of the proximal end of the assembly that is disposed outside the patient. Usually, the catheter assembly is secured to the torso of the patient in a manner to prevent any dislocation of the distal tips of the catheter lumens from any movement along the vessel after initial placement at the catheterization site. However, certain catheter assemblies, termed PICC catheters (for peripherally inserted central catheters), are implanted through a vessel entry on an arm of the patient, known as axillary placement. The remainder of the catheter is disposed in the vasculature of the patient (the distal end portion) or in a subcutaneous tunnel in order to anchor the catheter assembly against any movement that would dislodge the position of the distal tip of the catheter from its precisely selected location in the patient's vasculature. Such implanted catheters are used for various procedures such as hemodialysis, infusion therapy and power injection such as of contrast agent.
The distal ends of the extension tubes enter the proximal end of a hub in order to be put in sealed fluid communication with proximal ends of respective lumens of the catheter that enter the distal end of the hub. Luer connectors are affixed on the proximal ends of the extension tubes for connection to and disconnection from tubing of the dialysis machine or other medical device, and a clamp such as a Roberts clamp is disposed along the length of each extension tube in order to be manipulated into a clamping state that prevents fluid flow through the extension tube while permitting fluid flow therethrough when manipulated into an unclamping state. The material of the extension tubes is selected such that it is better able to resume its full diameter when the clamp is unclamped.
It is desired to provide a low profile hub for establishing the connections of three extension tubes to the proximal ends of respective lumens of a triple lumen catheter, especially for PICC catheter assemblies, where the hub is located along the patient's arm.